Easy

Are Irradiated Gemstones Dangerous

Out of all of the gemstone treatments
currently on the market there is one treatment that always raises questions.
That treatment is irradiation. When the words “irradiation” are whispered the
first thing that springs to mind is ‘is it safe’? The good news is yes it is. We
will explore why gemstones are irradiated and what the NRC (Nuclear Regulatory
Commission) do to ensure your safety.

The gemstone that has caused so much
discussion is blue Topaz. Since the 80’s this gemstone has routine undergone
irradiation to give it the blue color that we all know and love. There are two
methods for irradiating blue Topaz. They both involve types of nuclear
reactors. The first is to use a stream of electrons to induce the color, the
other is to use a stream of neutrons. While the electron method produces Topaz
that does not pose a hazard to humans the neutron Topaz can continue to emit
radiation for years. After extensive research from various bodies including the
NRC rigorous checks have been put in place to ensure all neutron irradiated
blue Topaz that comes to market is safe to handle.

What Gemstones Are Commonly Irradiated?

The below list gives an example of the
colors that can be achieved with irradiation. This is not a complete list and
other color variations are available.

There are three main ways to irradiate
gemstones. Each method uses a different facility and can have different effects
on gemstones.

Neutron Bombardment – Use of a nuclear
reactor

Electron (Beta) Bombardment – Use of an
accelerator

Gamma radiation – Use of a cobalt-60
facility (these facilities are commonly used to sterilize medical equipment)

The irradiation process can be thought of
like balls. The neutron method fires large tennis balls at the subject and
induces the color. The electron method uses tiny balls to fire at the subject.
Gamma radiation uses microscopic balls with huge amounts of energy to induce
the color.

Does Irradiation Make The Gemstone
Radioactive

The longer a gemstone is exposed to
irradiation the more chance of the stone becoming radioactive. The reason why
gemstones become radioactive is if impurities within the gemstone become
active. Stones treated with either electron or neutron irradiation will remain
radiaoactive for a period of time. Stones treated with gamma radiation will not
become radiactive.

For stone treated with electron irradiation
the radiation level of the material that comes out of the reactor is generally
deemed safe to handle by the NRC. Even still there are strict guidelines in
place to ensure that the Topaz is set aside for a number of months. Remember
that radiation decays over time so if the stones are safe to handle straight
out of the reactor they are safe to handle once they come to market.

Neutron radiation takes a longer period to
become safe. According to the NRC the average time for freshly neutron
irradiated Topas to become safe is 12 – 24 months.

How Much Radiation Will I Be Exposed To?

Radiation is everywhere. It is a natural
part of life and we actually can’t live without it. Lets do some quick
comparisons. Radiation is measured by millirium or Radiation Absorbance Dose.

A 6ct Topaz worn for a year (assuming the radiation
level is at the maximum that the NRC deem to be safe) = 0.03 millerium

Lets compare some other common thing (all
based on 1 year exposure)

Porcelain Crown or False Teeth = 0.07
millerium (2.3x that of Topaz)

Chest X-ray = 10 millerium (333x that of
Topaz)

Food and Water (yes even that has natural
radiation) = 30 millerium (1,000x that of Topaz)

Trans Atlantic Flight = 2.5 millerium (83x
that of Topaz)

Watching TV = 1 millerium (33x that of Topaz)

How Does Irradiation Cause Color?

Obviously this is a very complex subject
but lets try and explain it. I will explain the two ways gemstones get their
color. Chromophores (impurities) and color centers (defects). Here we go

Chromophore. This is when a mineral has
impurities which cause color. Take Sapphire for example. Pure Sapphire is clear.
Add in Titanium as an impurity and it turns blue. Add in Iron it turns yellow.
Add Chromium it turns pink. Add iron and Chromium and you get orange / pink
(padparascha). This is the most common way gems get their color. So if you want
to enhance a Sapphire, you can diffuse Titanium to the Sapphire and create a
bluer stone (Surface diffusion).

So if you take Kunzite, Topaz, Hiddenite,
Diamond and try and induce a defect in the crystal lattice, you will induce
color.

How do you cause a defect? You smash the
atoms inside the crystal with something. This is where the electron radiation
and neutron radiation comes in. You literally smash the gem with radiation to
cause a defect which causes color.

Is The Color Permanent?

These defects can be fixed by applying
energy to the gem. In the case of Kunzite, this energy is in the form of UV radiation
from the sun. The energy from the sun repairs the crystal structure and removes
the pink color from the gem.

You will see plenty of irradiated Hiddenite
in the market which has been irradiated. It has a color center induced which causes
the green color. This color is sensitive to sunlight just like Kunzite.

The color in Topaz and Tourmaline for
example is stable. The process for creating the blue color in Topaz involves
irradiating the gemstone and then heating it. This heating process actually
stabiles the color and creates a gem that will not fade or deteriorate over
time.

Some of the brown Topaz you will see is the
result of electron radiation of Topaz. If this Topaz is heated, it will turn
blue and stablise the color. However a
few years ago someone decided they would Irradiate Topaz but when it turned
Brown with an orange tinge they decided not to heat it and turn it blue but to
sell it as imperial Topaz. Sites like Gem Rock Auctions do not allow these
types of stones to be sold as Imperial Topaz.

Now that you know how safe irradiated gemstones are it is time to decide if you really want to wear those false teeth. Afterall would you rather a set of false teeth or twice the number of Topaz gemstones.